Poly(Cannabinoid)s, Natural Polymers Fit for Green Chemistry

A major contributor to the rise of large-scale hemp production in the United States is the harvesting of cannabinoids such as cannabidiol, which can make up more than 18% of the plant’s dry weight.¹ However, the small molecule structure of cannabinoids has limited their incorporation into plastic materials despite their potential as a relatively inexpensive and environmentally safe polymer feedstock. Poly(cannabinoid)s are the first materials to include cannabinoids directly in their polymeric backbone. When compared to cannabidiol (CBD), poly(cannabidiol-adipate) demonstrates a nearly doubled degradation temperature of 361 °C and prevents the conversion of CBD to other cannabinoids such as Δ9-tetrahydrocannabinol. In addition, poly(CBD-adipate) can be drawn into fibers or cast as a semicrystalline film having a broad melting temperature range of 100 to 250 °C. These properties, along with the material’s glass transition temperature of 41 °C, suggest it can be processed into different macrostructures to suit a variety of applications.² The potential of poly(cannabinoid)s as a good alternative to petroleum plastics is further supported by their ester-containing backbone which can be hydrolyzed to produce the original cannabinoid and linking monomer, one of many nontoxic aliphatic dicarboxylic acids chosen to fit the application.<br/> <br/> <br/><b>References:</b><br/>1. VanDolah, H. J.; Bauer, B. A.; Mauck, K. F. Clinicians’ Guide to Cannabidiol and Hemp Oils. <i>Mayo Clin. Proc.</i> <b>2019</b>, <i>94</i> (9), 1840–1851. https://doi.org/10.1016/j.mayocp.2019.01.003.<br/>2. Daniels, R.; Yassin, O.; Mao J.; Mutlu Z.; Jain M.; Valenti J.; Cakmak M; Sotzing G. Poly(Cannabinoid)s. Reconstitution of Cannabis Sativa’s Naturally-Occuring Diols into Thermally Stable, Biodegradable Polyesters. <i>J. Am. Chem. Soc.</i>, submitted for publication, <b>2021</b>.